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Nest M15 or setup says added but incomplete
M15 is an account/setup pairing problem. Google’s documented fix is to reset the device/account setup state or resume the incomplete setup—not to rewire…
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M15 is an account/setup pairing problem. Google’s documented fix is to reset the device/account setup state or resume the incomplete setup—not to rewire the thermostat.
Check these first
- Read whether thermostat says it could not be added or app shows incomplete.
- Confirm model generation because setup flow differs.
Fix it in this order
- For M15 “couldn’t be added”, use Reset Device as Google directs and restart setup.
- For “Added” + INCOMPLETE, resume setup in the app.
- Only remove/re-add after the documented resume/reset options fail.
Evidence to keep
- M15/incomplete screen
- Model generation
- Account/app result
Do not make it harder
- Changing HVAC wiring for an account setup error
How you know it is fixed
- Thermostat appears normally in the correct home/account and setup is complete.
If the obvious fix does not work
- If account setup completes but Wi-Fi later drops, move to offline/W-code troubleshooting.
- If app alone is broken on one phone, test another device/network before resetting the thermostat.
If this still isn't resolved
- Google Nest Support
Sources for this path
Use these references to confirm provider-, model-, policy-, or jurisdiction-specific details before an irreversible step.
Need the complete context?
This page solves one branch. The parent guide covers the full decision, edge cases, alternatives, and related checks.